Photographic tray.



w. e. RICE. PHOTOGRAPHIG TRAY.

APPLICATION FILED JULY 24, 1909.

Patented May 2, 1911.

I i r]...

THE NORRIS PETERS co., WASHINGTON. LL I;

'UNTED STATES PATENT FFTfiE.

WALDO G. RICE, 0F EDISON PARK, ILLINOIS.

PHOTOGRAPHIG TRAY.

To all whom it may concern:

Be it known that I, VALDO Gr. RICE, a citizen of the United States,residing at Edison Park, in the county of Cook and State of Illinois,have invented certain new and useful Improvements in Photographic Trays,of which the following is a specification.

My invention relates to photographic apparatus and has especialreference to developing trays.

It is well known that in the successful development of a sensitive platethere are a number of elements to be taken into consideration,differences in the developing agents and variations in the formulae andthe proportions of the ingredients in the same formula being ofimportance, and in addition to these are the essential factors of timeand temperature, and as the temperature of the developing agent willhave a large influence upon the time required to produce a certainresult, some means that will enable the operator to quickly and accurately ascertain the precise temperature of the contents of the trayduring the process of developing without in any way interfering withthat process, will prove of great advantage in such work.

The chief objects of the improvements which constitute the subjectmatter of this application are, to provide a thermometric attachment fora negative developing tray whereby the temperature of the developingfluid contained in said tray may be conveniently ascertained and to soarrange the said attachment that the indicated temperature may beobserved without removing the cover or exposing the contents of the trayto the action of actinic rays.

Further objects of the invention are :To furnish a device for thepurpose stated, that will be protected from injury by a suitable housingsupplied with a transparent covering through which the thermal scale maybe easily read, and to so arrange the indicator that there will be noprojections above the outer surface of the tray, thus avoiding anydetraction from the appearance of the developing utensil.

I accomplish the desired results by the development of the deviceillustrated in the accompanying drawing which forms a part of thisapplication the important details of Specification of Letters Patent.

Application filed July 24, 1909.

Patented May 2, 1911.

Serial No. 509,372.

construction being disclosed in the following views Figure 1 is a topplan View of a photographic developing tray embodying my invention; Fig.2 is a sectional view on the line 2-2 of Fig. 1; Fig. 3 is a fragmentarysection on the line 33 of Fig. 1 and Fig. i is a fragmentary view of thecover showing the cylindrical housing for the thermometer bulb.

Referring to the details of the drawing, the numeral 5 indicates thesides and 6 the bottom of a rectangular developing tray having steppedledges or shoulders 7 extending entirely about the periphery of the trayupon the inner wall, the said ledges being higher along the sides thanat the ends of the tray. A cover 8 fitting within the tray has aperipheral flange 9 extending entirely around the cover a short distancefrom the margin and parallel therewith thus forming steps or shoulders10 adapted to rest upon or interlock with the said shoulders 7, thusforming a light excluding joint. As the end ledges are lower than thoseat the side there will be a space 7 between the shoulders at each endthrough which the developing fluid may be poured without removing thecover. As a precaution against the possible trickling of light throughthe interval the under surface of the cover is provided with downwardlyprojecting shields 10.

The cover is supplied with a central projection 11 which serves as ahandle, and is provided upon its under side near one margin with areinforcement or boss 12, through which is formed a circular aperture 13counterbored below as indicated at 14 to admit a cylindrical cap orhousing 15, closed at the lower end 16. The upper face of the cover isfurnished with a groove 17 one end of which communicates with theaperture 13 and in this groove is arranged the greater portion of thestem 18 of a thermometer. This stem is bent at a right angle at a point19, a suitable distance from the bulb 20, the latter occupying thecasing or housing 15, and extending to within a short distance of theclosed end 16. In order to secure the thermometer in its seat and toprotect the exposed side, I cover the groove 17 and aper ture 13 with atransparent plate 21, preferably made of celluloid, which is let into arecess 22 formed in the cover so that the said plate will be flush withthe surface. This recess is made slightly deeper than the thickness ofthe transparent plate to accommodate a thin plate 23 which may be ofmetal or card board or if preferred of paper, upon which are printed orimpressed suitable graduations calibrated to form a thermoinetric scale24: and a time scale '25, indicating respectively degrees of temperatureand times of exposure corresponding therewith. This plate or scale issupplied with a slot 26 which permits the entire horizontal portion ofthe thermometer stem to be exposed so that the height of the mercurycolumn may be readily compared with the scale.

It is necessary to place the cup or housing close to one side of thetray in order that it may not interfere with the sensitive plate, andthe tray wall at this point is cut away forming a recess 27 to receivethe said housing 15 and as the side walls of the tray are chamferedopposite the location of the steps or ledges 7, as indicated at 28, thispart of the wall is thickened or reinforced as shown at 29 to preventweakening of the wall by said recess.

In order to provide for more perfect conduction of the heat from thetray contents to the bulb of the thermometer, the housing 15 is filledwith mercury 30 which thus surrounds said bulb, materially increasingthe sensitiveness of the instrument and enabling it to give an accurateindication of the temperature condition of the developing liquid. Toprevent the mercury from escaping from the cell the upper part of thecavity 15 is sealed by a suitable layer of waX or cement 31.

The manner of using my improved thermometric developing tray will bereadily understood by those skilled in the art. The tray having beensupplied with the required amount of the reagent, the sensitive plateimmersed therein and the cover then applied in the usual manner, therewill be no occasion for further observation of the plate, during thedeveloping process since all the data necessary may be obtained by thethermometer reading compared with the temperature coefficients of thescale s5.

lVhile this device is especially applicable to thermo-development, thetray, when thus equipped, is not disqualified for the factorial methodof treating the sensitive plate.

Having thus described my invention, what I claim as new, is:

1. In a photographic developing tray including a receptacle and a coverhaving cooperating light excluding portions on the inner walls of thereceptacle and the edges of the cover, and said cover having an openingtherethrough, a thermometer having its bulb extending through saidopening into the tray and its stem fitting a recess in the top of thecover, a scale-bearing member arranged on said cover in operativerelation to said thermometer, and means for preventing the passage oflight through the opening in said cover around said bulb.

2. In a photographic developing tray, including a cover having anopening therethrough and with a recess in the upper face thereof and agroove in the bottom of said recess communicating with said opening, athermometer having its stem arranged in said groove and its lower endbent to extend through said opening, a protective casing for said lowerend, a transparent protective plate for said stem arranged in saidrecess. and, a scale card in said recess beneath said plate.

In testimony whereof I aflix my signature in the presence of twowitnesses.

Vi-UAW (l. RICE.

Witnesses NI. A. MiLonn, CHAS. F. BASSET'J.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). C.

